1. Field
A composition for an optical film, films, and a display device are disclosed.
2. Description of the Related Art
Commonly used flat panel displays may be classified into a light-emitting display device emitting light by itself and a non-emissive display device requiring a separate light source. An optical film such as a retardation film is frequently employed for improving the image quality thereof.
In the case of the light emitting display device, for example, an organic light emitting display, the visibility and the contrast ratio may be deteriorated by reflection of external light caused by a metal such as an electrode. In order to reduce this, the linear polarized light is changed into circularly polarized light by using a polarizer and an optical film, to prevent the reflection of the external light by the organic light emitting display and leakage thereof.
A liquid crystal display (LCD) as a non-emissive display device uses an optical film and secures a wide viewing angle thereby. Thus, it may compensate retardation generated by liquid crystals.
An optical film obtained by stacking polymer films having different refractive indexes has been suggested. However, the stacked optical film has a disadvantage in that it alters the thinness of a display device. In addition, the stacked optical film requires a separate process of adhering the polymer films by using an adhesion layer and the like after respectively manufacturing the polymer films. Thus, the stacked optical film may also bring about display defects due to a stain by the adhesion, mixing of a foreign material, and the like as well as needing a complex process.
There remains a need in an optical film capable of simplifying a process of making the display device and improving its display characteristics without increasing the thickness of the device.